Project IV extends our previous neuroimaging project which developed rigorous methodologies to examine particular brain structures between well-described subject groups and will also compare measures of brain function in these cohort. In our previous efforts, we obtained neuroanatomical Magnetic Resonance studies on over 320 children. While rigorous studies were performed on some of these subjects, complete image analysis was hampered by limitations in the subject groups, especially the normal group, due to necessary subtyping by gender and handedness. In this new grant, we propose to capitalize on our previous efforts by first performing additional MR neuroanatomical imaging using the same protocols as before on additional normal subjects in order to form a more complete control group. Next, rigorous statistical testing can be performed on the corpus callosum and the temporal lobes (focusing on planum temporale) using the sum total of this data. This neuroanatomical structures analysis will also be extended to include a measurement related to the asymmetry of the caudate nucleus. At the end of this effort, we hope to carefully and rigorously affirm or refute a variety of hypotheses relating brain structure and learning disorders currently being reported in the literature. In addition, not only do we plan to extend our previous studies of brain structure, but we also plan a major effort to examine brain function using non-invasive magnetic resonance imaging techniques in well- characterized reading disabled children to measure changes in blood flow in specific brain regions during specific cognitive tasks. Here, we will first develop methodology that will permit us to evaluate differences in the brain's response to different activation tasks in the frontal cortex and the temporal lobes. Next, we will compare these changes in children from three subject groups: dyslexic, attention disordered and normal children. MR promises to be the first method suitable for functional changes.